NY Times Article on Sunni-Shi’i Sectarian Mapping

Sunni-led allies of Saudi Arabia have cut diplomatic ties with Shiite Iran, further polarizing the Middle East along the two major branches of Islam. But while almost all of the governments are controlled by one sect, the countries’ populations are a mix of Sunnis and Shiites, as well as other branches and sub-sects, an important and complicating factor in the region’s conflicts.